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package com.nubotech.gwt.oss.client.util;

/**
 *
 * @author jonnakkerud
 */
public class Sha1 {

    private static final boolean hexcase = false;/* hex output format. false - lowercase; true - uppercase */

    private static final String b64pad = "="; /* base-64 pad character. "=" for strict RFC compliance */

    private static final int chrsz = 8; /* bits per input character. 8 - ASCII; 16 - Unicode */


    /**
     * This is one of the functions you'll usually want to call
     * It take a string arguments and returns either hex or base-64 encoded strings
     * Creation date: (3/27/2004 6:05:10 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return java.lang.String
     * @param key java.lang.String
     * @param data java.lang.String
     */
    public static String b64_hmac_sha1(String key, String data) {
        return binb2b64(core_hmac_sha1(key, data));
    }

    /**
     * This is one of the functions you'll usually want to call
     * It take a string argument and returns either hex or base-64 encoded strings
     * Creation date: (3/27/2004 6:05:10 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return java.lang.String
     * @param s java.lang.String
     */
    public static String b64_sha1(String s) {
        s = (s == null) ? "" : s;
        return binb2b64(core_sha1(str2binb(s), s.length() * chrsz));
    }

    /**
     * Convert an array of big-endian words to a base-64 string
     * Creation date: (3/27/2004 6:05:10 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return java.lang.String
     * @param binarray int[]
     */
    private static String binb2b64(int[] binarray) {
        String tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
        String str = "";
        binarray = strechBinArray(binarray, binarray.length * 4);
        for (int i = 0; i < binarray.length * 4; i += 3) {
            int triplet =
                    (((binarray[i >> 2] >> 8 * (3 - i % 4)) & 0xFF) << 16) | (((binarray[i + 1 >> 2] >> 8 * (3 - (i + 1) % 4)) & 0xFF) << 8) | ((binarray[i + 2 >> 2] >> 8 * (3 - (i + 2) % 4)) & 0xFF);
            for (int j = 0; j < 4; j++) {
                if (i * 8 + j * 6 > binarray.length * 32) {
                    str += b64pad;
                } else {
                    str += tab.charAt((triplet >> 6 * (3 - j)) & 0x3F);
                }
            }
        }
        return cleanB64Str(str);
    }

    /**
     * Convert an array of big-endian words to a hex string.
     * Creation date: (3/27/2004 6:05:10 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return java.lang.String
     * @param binarray int[]
     */
    private static String binb2hex(int[] binarray) {
        String hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
        String str = "";
        for (int i = 0; i < binarray.length * 4; i++) {
            char a = (char) hex_tab.charAt((binarray[i >> 2] >> ((3 - i % 4) * 8 + 4)) & 0xF);
            char b = (char) hex_tab.charAt((binarray[i >> 2] >> ((3 - i % 4) * 8)) & 0xF);
            str += (new Character(a).toString() + new Character(b).toString());
        }
        return str;
    }

    /**
     * Convert an array of big-endian words to a string
     * Creation date: (3/27/2004 6:05:10 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return java.lang.String
     * @param bin int[]
     */
    private static String binb2str(int[] bin) {
        String str = "";
        int mask = (1 << chrsz) - 1;
        for (int i = 0; i < bin.length * 32; i += chrsz) {
            str += (char) ((bin[i >> 5] >>> (24 - i % 32)) & mask);
        }
        return str;
    }

    /**
     * Bitwise rotate a 32-bit number to the left.
     * Creation date: (3/26/2004 1:05:01 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return int
     * @param num int
     * @param cnt int
     */
    private static int bit_rol(int num, int cnt) {
        return (num << cnt) | (num >>> (32 - cnt));
    }

    /**
     * Cleans a base64 String from all the trailing 'A' or other
     * characters put there by binb2b64 that made the bin array
     * 4 times larger than it originally was.
     * Creation date: (3/27/2004 6:05:10 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return java.lang.String
     * @param str java.lang.String
     */
    private static String cleanB64Str(String str) {
        str = (str == null) ? "" : str;
        int len = str.length();
        if (len <= 1) {
            return str;
        }
        char trailChar = str.charAt(len - 1);
        String trailStr = "";
        for (int i = len - 1; i >= 0 && str.charAt(i) == trailChar; i--) {
            trailStr += str.charAt(i);
        }
        return str.substring(0, str.indexOf(trailStr));
    }

    /**
     * Makes an int array of a length less than 16 an array of length 16 with all previous
     * cells at their previous indexes.
     * Creation date: (3/27/2004 6:05:10 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return int[]
     * @param str java.lang.String
     */
    private static int[] complete216(int[] oldbin) {
        if (oldbin.length >= 16) {
            return oldbin;
        }
        int[] newbin = new int[16 - oldbin.length];
        for (int i = 0; i < newbin.length; newbin[i] = 0, i++);
        return concat(oldbin, newbin);
    }

    /**
     * Joins two int arrays and return one that contains all the previous values.
     * This corresponds to the concat method of the JavaScript Array object.
     * Creation date: (3/27/2004 6:05:10 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return int[]
     * @param str java.lang.String
     */
    private static int[] concat(int[] oldbin, int[] newbin) {
        int[] retval = new int[oldbin.length + newbin.length];
        for (int i = 0; i < (oldbin.length + newbin.length); i++) {
            if (i < oldbin.length) {
                retval[i] = oldbin[i];
            } else {
                retval[i] = newbin[i - oldbin.length];
            }
        }
        return retval;
    }

    /**
     * Calculate the HMAC-SHA1 of a key and some data
     * Creation date: (3/26/2004 1:05:01 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return int
     * @param x java.lang.String[]
     * @param len int
     */
    private static int[] core_hmac_sha1(String key, String data) {
        key = (key == null) ? "" : key;
        data = (data == null) ? "" : data;
        int[] bkey = complete216(str2binb(key));
        if (bkey.length > 16) {
            bkey = core_sha1(bkey, key.length() * chrsz);
        }
        int[] ipad = new int[16];
        int[] opad = new int[16];
        for (int i = 0; i < 16; ipad[i] = 0, opad[i] = 0, i++);
        for (int i = 0; i < 16; i++) {
            ipad[i] = bkey[i] ^ 0x36363636;
            opad[i] = bkey[i] ^ 0x5C5C5C5C;
        }
        int[] hash =
                core_sha1(concat(ipad, str2binb(data)), 512 + data.length() * chrsz);
        return core_sha1(concat(opad, hash), 512 + 160);
    }

    /**
     * Calculate the SHA-1 of an array of big-endian words, and a bit length
     * Creation date: (3/26/2004 1:05:01 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return int
     * @param x java.lang.String[]
     * @param len int
     */
    private static int[] core_sha1(int[] x, int len) {
        /* append padding */
        int size = (len >> 5);
        x = strechBinArray(x, size);
        x[len >> 5] |= 0x80 << (24 - len % 32);
        size = ((len + 64 >> 9) << 4) + 15;
        x = strechBinArray(x, size);
        x[((len + 64 >> 9) << 4) + 15] = len;
        int[] w = new int[80];
        int a = 1732584193;
        int b = -271733879;
        int c = -1732584194;
        int d = 271733878;
        int e = -1009589776;
        for (int i = 0; i < x.length; i += 16) {
            int olda = a;
            int oldb = b;
            int oldc = c;
            int oldd = d;
            int olde = e;
            for (int j = 0; j < 80; j++) {
                if (j < 16) {
                    w[j] = x[i + j];
                } else {
                    w[j] = rol(w[j - 3] ^ w[j - 8] ^ w[j - 14] ^ w[j - 16], 1);
                }
                int t =
                        safe_add(
                        safe_add(rol(a, 5), sha1_ft(j, b, c, d)),
                        safe_add(safe_add(e, w[j]), sha1_kt(j)));
                e = d;
                d = c;
                c = rol(b, 30);
                b = a;
                a = t;
            }
            a = safe_add(a, olda);
            b = safe_add(b, oldb);
            c = safe_add(c, oldc);
            d = safe_add(d, oldd);
            e = safe_add(e, olde);
        }
        int[] retval = new int[5];
        retval[0] = a;
        retval[1] = b;
        retval[2] = c;
        retval[3] = d;
        retval[4] = e;
        return retval;
    }

    /**
     * Just a test function to output the results of the 6 working funcions to the standard out.
     * The two Strings used as parameters are null. Feel free to test with different values.
     * Creation date:(3/27/20046:05:10PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return java.lang.String
     */
    private static void doTest() {
        String key = "key";
        String data = "data";
        System.out.println("hex_sha1(" + data + ")=" + hex_sha1(data));
        System.out.println("b64_sha1(" + data + ")=" + b64_sha1(data));
        System.out.println("str_sha1(" + data + ")=" + str_sha1(data));
        System.out.println("hex_hmac_sha1(" + key + "," + data + ")=" + hex_hmac_sha1(key, data));
        System.out.println("b64_hmac_sha1(" + key + "," + data + ")=" + b64_hmac_sha1(key, data));
        System.out.println("str_hmac_sha1(" + key + "," + data + ")=" + str_hmac_sha1(key, data));
    }

    /**
     * This is one of the functions you'll usually want to call
     * It take a string arguments and returns either hex or base-64 encoded strings
     * Creation date: (3/27/2004 6:05:10 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return java.lang.String
     * @param key java.lang.String
     * @param data java.lang.String
     */
    public static String hex_hmac_sha1(String key, String data) {
        return binb2hex(core_hmac_sha1(key, data));
    }

    /**
     * This is one of the functions you'll usually want to call
     * It take a string argument and returns either hex or base-64 encoded strings
     * Creation date: (3/27/2004 6:05:10 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return java.lang.String
     * @param s java.lang.String
     */
    public static String hex_sha1(String s) {
        s = (s == null) ? "" : s;
        return binb2hex(core_sha1(str2binb(s), s.length() * chrsz));
    }

    /**
     * Bitwise rotate a 32-bit number to the left. * Creation date: (3/26/2004 1:05:01 PM)
     * Creation date: (3/27/2004 6:05:10 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return int
     * @param num int
     * @param cnt int
     */
    private static int rol(int num, int cnt) {
        return (num << cnt) | (num >>> (32 - cnt));
    }

    /**
     * Add ints, wrapping at 2^32. This uses 16-bit operations internally
     * to work around bugs in some JS interpreters. The original function
     * is part of the sha1.js library. It's here for compatibility.
     * Creation date: (3/26/2004 1:05:01 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return int
     * @param num int
     * @param cnt int
     */
    private static int safe_add(int x, int y) {
        int lsw = (int) (x & 0xFFFF) + (int) (y & 0xFFFF);
        int msw = (x >> 16) + (y >> 16) + (lsw >> 16);
        return (msw << 16) | (lsw & 0xFFFF);
    }

    /**
     * Perform the appropriate triplet combination function for the current
     * Creation date: (3/26/2004 1:05:01 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return int
     * @param t int
     * @param b int
     * @param c int
     * @param d int
     */
    private static int sha1_ft(int t, int b, int c, int d) {
        if (t < 20) {
            return (b & c) | ((~b) & d);
        }
        if (t < 40) {
            return b ^ c ^ d;
        }
        if (t < 60) {
            return (b & c) | (b & d) | (c & d);
        }
        return b ^ c ^ d;
    }

    /**
     * Determine the appropriate additive constant for the current iteration
     * Creation date: (3/26/2004 1:05:01 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return int
     * @param t int
     */
    private static int sha1_kt(int t) {
        return (t < 20)
                ? 1518500249
                : (t < 40)
                ? 1859775393
                : (t < 60)
                ? -1894007588
                : -899497514;
    }

    /**
     * This is a boolean returnig test function that exists in the sha1.js library.
     * If it returns 'false' something is wrong.
     * Creation date: (3/26/2004 1:05:01 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return java.lang.String
     * @param s java.lang.String
     */
    private static boolean sha1_vm_test() {
        return hexcase ? hex_sha1("abc").equals("A9993E364706816ABA3E25717850C26C9CD0D89D") : hex_sha1("abc").equals("a9993e364706816aba3e25717850c26c9cd0d89d");
    }

    /**
     * This is one of the functions you'll usually want to call
     * It take a string arguments and returns either hex or base-64 encoded strings
     * Creation date: (3/26/2004 1:05:01 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return java.lang.String
     * @param key java.lang.String
     * @param data java.lang.String
     */
    public static String str_hmac_sha1(String key, String data) {
        return binb2str(core_hmac_sha1(key, data));
    }

    /**
     * This is one of the functions you'll usually want to call
     * It take a string argument and returns either hex or base-64 encoded strings
     * Creation date: (3/26/2004 1:05:01 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return java.lang.String
     * @param s java.lang.String
     */
    public static String str_sha1(String s) {
        s = (s == null) ? "" : s;
        return binb2str(core_sha1(str2binb(s), s.length() * chrsz));
    }

    /**
     * Convert an 8-bit or 16-bit string to an array of big-endian words
     * In 8-bit function, characters >255 have their hi-byte silently ignored.
     * Creation date: (3/26/2004 1:05:01 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return int[]
     * @param str java.lang.String
     */
    private static int[] str2binb(String str) {
        str = (str == null) ? "" : str;
        int[] tmp = new int[str.length() * chrsz];
        int mask = (1 << chrsz) - 1;
        for (int i = 0; i < str.length() * chrsz; i += chrsz) {
            tmp[i >> 5] |= ((int) (str.charAt(i / chrsz)) & mask) << (24 - i % 32);
        }

        int len = 0;
        for (int i = 0; i < tmp.length && tmp[i] != 0; i++, len++);
        int[] bin = new int[len];
        for (int i = 0; i < len; i++) {
            bin[i] = tmp[i];
        }
        return bin;
    }

    /**
     * increase an int array to a desired sized + 1 while keeping the old values.
     * Creation date: (3/26/2004 1:05:01 PM)
     * @author T.N.Silverman
     * @version 1.0.0
     * @return int[]
     * @param str java.lang.String
     */
    private static int[] strechBinArray(int[] oldbin, int size) {
        int currlen = oldbin.length;
        if (currlen >= size + 1) {
            return oldbin;
        }
        int[] newbin = new int[size + 1];
        for (int i = 0; i < size; newbin[i] = 0, i++);
        for (int i = 0; i < currlen; i++) {
            newbin[i] = oldbin[i];
        }
        return newbin;
    }
}